1. Field of the Invention
The present invention generally relates to a method of atomic layer etching (ALE), particularly to a method of plasma-enhanced ALE (PEALE).
2. Description of the Related Art
In order to cope with various processing accompanying microminiaturization and complex structures of semiconductor devices, precision of processing has been remarkably improved by new technology such as double-patterning. However, conventional etching technology such as continuous etching using excited reaction species may be difficult to form fine, narrow convex-concave patterns and may cause defects of shape. Thus, development of etching technology which is capable of performing atomic layer-level etching and is suitable for e.g., double-patterning processes, becomes important. However, low etching rate, poor controllability over directionality of etching, or the like need to be improved.
Any discussion of problems and solutions in relation to the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion was known at the time the invention was made.